WORMS

FLATWORMS =“Platyhelminthes” Planaria – free living Tapeworms - parasitic Flukes - parasitic

PLANARIA Free living/aquatic ACOELOMATES (NO body cavity) No TEGUMENT or CUTICLE DIGESTIVE/CIRCULATORY Combined gastrovascular cavity Only 1 opening to digestive system Mouth at end of tube in middle of body

PLANARIA NERVOUS Cerebral ganglia with 2 nerve cords Eyespots can detect light Simple learning EXCRETORY FLAME CELLS remove excess water RESPIRATORY Exchange gases through skin

PLANARIA REPRODUCTIVE Hermaphrodites trade sperm with other worms lay eggs in protective sac on rocks Ability to regenerate (regrow lost parts) can be used to reproduce asexually

TAPEWORMS Parasites that live in the intestines of all vertebrates Scolex with hooks and suckers on anterior end help it hold on

TAPEWORMS ACOELOMATES TEGUMENT- Protective covering made of cells Resists digestive enzymes/fools immune system NO DIGESTIVE SYSTEM/no mouth absorb nutrients that you digest through their skin EXCRETORY/NERVOUS SYSTEM Similar to Planaria but no eyes

TAPEWORMS REPRODUCTIVE Hermaphrodites- can fertilize self or trade sperm with other worms Grow by adding PROGLOTTIDS which contain both male and female reproductive organs 30 foot worm can have 2000 proglottids

PARASITIC WORMS Adult lives and reproduces in PRIMARY HOST Larval form lives in INTERMEDIATE HOST

HOW DO THEY INFECT HUMANS? Primary host: Human Intermediate host: cow

FLUKES Parasites No coelom Leaf shaped body Covered by TEGUMENT for protection

FLUKES DIGESTIVE/CIRCULATORY Anterior/Posterior suckers help it hold on 1 opening into a gastrovascular cavity NERVOUS Cerebral ganglia with 2 nerve cords but no eyes

FLUKES REPRODUCTIVE Most hermaphrodites/some separate sexes Fertilized eggs leave body in feces or urine Complicated life cycle with 2 hosts Adults- sexual reproduction Larva – asexual reproduction

HOW DO THEY INFECT HUMANS? Primary host: Human Larva burrow into skin Intermediate host: snail

ROUND WORMS “NEMATODES” Ascaris Trichinella Hookworms Pinworms Filarial worms

ROUND WORMS “NEMATODES” Many free living/some parasites PSEUDOCOELOMATES – body cavity only lined on one side with mesoderm Covered with CUTICLE(non-cellular) for protection 2 separate sexes

ROUND WORMS “NEMATODES” REPRODUCTIVE Separate sexes DIGESTIVE Digestive tract with 2 openings like Earthworms

ROUND WORMS “NEMATODES” Ascaris – enter by contaminated food/water live in intestines only 1 host Trichinella – enter by eating meat with cysts live in intestine Pork host- causes Trichinosis

ROUND WORMS “NEMATODES” Hook worms – live in intestine release eggs in feces larva burrow into feet Pinworms – Most common in U.S.A. live in lower digestive system females migrate out at night to lay eggs on skin infected by ingesting eggs

ROUND WORMS “NEMATODES” ELEPHANTIASIS worms live in lymph system blockage causes limbs to swell transmitted by mosquitoes Dog heartworm is also a filarial worm

SEGMENTED WORMS “Annelids” COELOMATES CUTICLE covers body for protection

SEGMENTED WORMS “Annelids” DIGESTIVE digestive system with 2 openings EXCRETORY NEPHRIDIA- remove water/nitrogen waste RESPIRATORY Exchange gases through skin

SEGMENTED WORMS “Annelids” REPRODUCTIVE Hermaphrodites- exchange sperm with partner Lay eggs in mucous sac left on ground

SEGMENTED WORMS “Annelids”